Two large sunspot groups, AR1875 and AR1877,have emerged over the sun's eastern limb and they are turning toward Earth. NASA's Solar Dynamics Observatory captured this three-day movie of their approach:

AR1877 is large, and AR1875 is rapidly growing to match it. Both sunspot groups have 'beta-gamma' magnetic fields that harbor energy for M-class solar flares. So far, however, neither one is actively flaring. Perhaps this is the calm before the storm. NOAA forecasters estimate a 25% chance of M-flares in the next 24 hours. www.spaceweather.com